- Geokit Documentation at Rubyforge http://geokit.rubyforge.org.
- Repository at Github: http://github.com/andre/geokit-gem/tree/master.
The Geokit gem provides the following:
- Distance calculations between two points on the earth. Calculate the distance in miles or KM, with all the trigonometry abstracted away by GeoKit.
- Geocoding from multiple providers. It currently supports Google, Yahoo, Geocoder.us, and Geocoder.ca geocoders, and it provides a uniform response structure from all of them. It also provides a fail-over mechanism, in case your input fails to geocode in one service.
- Rectangular bounds calculations: is a point within a given rectangular bounds?
- Heading and midpoint calculations
Combine this with gem with the geokit-rails plugin to get location-based finders for your Rails app. Plugins for other web frameworks and ORMs will provide similar functionality.
irb> require 'rubygems'
irb> require 'geokit'
irb> a=Geokit::Geocoders::YahooGeocoder.geocode '140 Market St, San Francisco, CA'
irb> a.ll
=> 37.79363,-122.396116
irb> b=Geokit::Geocoders::YahooGeocoder.geocode '789 Geary St, San Francisco, CA'
irb> b.ll
=> 37.786217,-122.41619
irb> a.distance_to(b)
=> 1.21120007413626
irb> a.heading_to(b)
=> 244.959832435678
irb(main):006:0> c=a.midpoint_to(b) # what's halfway from a to b?
irb> c.ll
=> "37.7899239257175,-122.406153503469"
irb(main):008:0> d=c.endpoint(90,10) # what's 10 miles to the east of c?
irb> d.ll
=> "37.7897825005142,-122.223214776155"
FYI, that .ll method means "latitude longitude".
See the RDOC more more ... there is also operations on rectangular bounds (e.g., determining if a point is within bounds, find the center, etc).
- gem sources -a http://gems.github.com
- sudo gem install andre-geokit
If you're using this gem by itself, here's how to set configurations:
# These defaults are used in Geokit::Mappable.distance_to and in acts_as_mappable
Geokit::default_units = :miles
Geokit::default_formula = :sphere
# This is the timeout value in seconds to be used for calls to the geocoder web
# services. For no timeout at all, comment out the setting. The timeout unit
# is in seconds.
Geokit::Geocoders::timeout = 3
# These settings are used if web service calls must be routed through a proxy.
# These setting can be nil if not needed, otherwise, addr and port must be
# filled in at a minimum. If the proxy requires authentication, the username
# and password can be provided as well.
Geokit::Geocoders::proxy_addr = nil
Geokit::Geocoders::proxy_port = nil
Geokit::Geocoders::proxy_user = nil
Geokit::Geocoders::proxy_pass = nil
# This is your yahoo application key for the Yahoo Geocoder.
# See http://developer.yahoo.com/faq/index.html#appid
# and http://developer.yahoo.com/maps/rest/V1/geocode.html
Geokit::Geocoders::yahoo = 'REPLACE_WITH_YOUR_YAHOO_KEY'
# This is your Google Maps geocoder key.
# See http://www.google.com/apis/maps/signup.html
# and http://www.google.com/apis/maps/documentation/#Geocoding_Examples
Geokit::Geocoders::google = 'REPLACE_WITH_YOUR_GOOGLE_KEY'
# This is your username and password for geocoder.us.
# To use the free service, the value can be set to nil or false. For
# usage tied to an account, the value should be set to username:password.
# See http://geocoder.us
# and http://geocoder.us/user/signup
Geokit::Geocoders::geocoder_us = false
# This is your authorization key for geocoder.ca.
# To use the free service, the value can be set to nil or false. For
# usage tied to an account, set the value to the key obtained from
# Geocoder.ca.
# See http://geocoder.ca
# and http://geocoder.ca/?register=1
Geokit::Geocoders::geocoder_ca = false
# This is the order in which the geocoders are called in a failover scenario
# If you only want to use a single geocoder, put a single symbol in the array.
# Valid symbols are :google, :yahoo, :us, and :ca.
# Be aware that there are Terms of Use restrictions on how you can use the
# various geocoders. Make sure you read up on relevant Terms of Use for each
# geocoder you are going to use.
Geokit::Geocoders::provider_order = [:google,:us]
If you're using this gem with the geokit-rails plugin, a template with these settings gets placed in your app's config/initializers directory.
mappable.rb contains the Mappable module, which provides basic distance calculation methods, i.e., calculating the distance between two points.
mappable.rb also contains LatLng, GeoLoc, and Bounds.
LatLng is a simple container for latitude and longitude, but
it's made more powerful by mixing in the above-mentioned Mappable
module -- therefore, you can calculate easily the distance between two
LatLng ojbects with distance = first.distance_to(other)
GeoLoc (also in mappable.rb) represents an address or location which has been geocoded. You can get the city, zipcode, street address, etc. from a GeoLoc object. GeoLoc extends LatLng, so you also get lat/lng AND the Mappable modeule goodness for free.
geocoders.rb contains all the geocoder implemenations. All the gercoders inherit from a common base (class Geocoder) and implement the private method do_geocode.
(The MIT License)
Copyright (c) 2007-2009 Andre Lewis and Bill Eisenhauer
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The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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